This is a 15-minute paper sundial in two senses: it takes 15-minutes to make and is labeled to the nearest 15-minutes. It is made of paper, but I designed the gnomon to have a three-dimensional base for greater stability, tapering to a thin top for better accuracy around noon.
The hard work was my doing the trigonometry for the three-dimensional paper-craft gnomon and writing a perl script that generates a pdf file for a particular location. But with the script written, you should be able to print out a sundial from the generator
on my website and construct it in fifteen minutes.Ingredients and tools:
- Two sheets of paper, ideally cardstock or some other heavy stock.
- Paper glue (I use Aleene's)
- Something pointy, e.g., a pen with no ink or a small screwdriver
- Computer with internet access, PDF viewer, and printer
The script I used was based loosely on the one in my large patio/driveway analemmatic sundial Instructable
. This is a much simpler project. The last one I assembled took 12 minutes once I had the design printed out and all the tools in place, and that's counting periodic stops to take photographs.
You can load the PDF file into a vector drawing application like Inkscape and make it fancier. Just make sure that if you resize the dial, you resize the gnomon (the pointer) in the same proportions. The script is open source so you can modify it as you see fit.
You can presumably trace the printout on copper sheets to make a fancier dial and gnomon. I'd love to see it.
This would make a good classroom project at various levels, depending on how deep you get into explaining how it works.Note:
The script currently works for latitudes between 24 degrees (north or south) and 65 degrees (north or south). (That covers all of the contiguous 48 states in the U.S., much of the populous parts of Canada and Europe, all of South Africa, much of India, etc.) The limitations are due to the way the gnomon is designed to work both when shadows are short and when they are long, and its having a wider base.